System of control.



H. A. STEEN.

SYSTEM OF CONTROL.

APPLICATION FILED NOV. 25, 1910.

2 SHEETS-SHEET 1.

H. A. STEEN.

SYSTEM OF CONTROL. APPLICATION FILED NOV-25, 1910.

Patented Aug. 3, 1915.

2 SHEETS-SHEET 2.

BMW

WW/2w $24 a, $4.?

UNITED STATES PATENT orrio.

HALFDAN A. STEEN, OF MILWAUKEE, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO ALLIS-CI-IALMERS MANUFACTURING COMPANY, A CORPORATION OF DELAWARE.

sYs'rEM or oonrnon.

Specification of Letters Patent.

Patented Aug. 3, 1915.

Application filed November 25, 1910. Serial No. 594,190.

To all whom it may concern:

Be it known that I, HALFDAN A. STnEN, a subject of the King of Norway, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Systems of Control, of which the following is a full, clear, and exact specification.

This invention relates to systems of control employing a controller of the separately actuated contact type in which the several controlling contacts are arranged to be operated automatically.

The object of the invention is to provide novel means in connection with my controller to prevent a too rapid successive operation of the control contacts thereof. The various novel features of my invention willbe described in the specification and particularly set forth in the appended claims.

My invention and a modification thereof are illustrated in Figures 1 and 2 respectively of the accompanying drawings.

The motor 10, here shown as having a shunt field 11, is connected to positive and negative mains 12 and 13 respectivelyby a switch 141- In order to vary the speed of the motor, sections 1' 1' and r of resistance are connected in series with the motor. These sections of resistance are adapted to be cut in and out of the motor circuit by automatically operated electromagnetic switches 1, 2, 3, and l, the operations of which are controlled by solenoids 15, 16, 17, and 18 included in an energizing circuit18 connected across the line. The energization of the solenoids 16, 17, and 18 is controlled by devices or members 19, 20, and 21 respectively'in series with said solenoids 16, 17 and 18. These devices are adapted to be included in the energizing circuit 18 and each comprises a member 22 having a negative resistance coefficient and a coil 23 adapted to heat themember 22 in order to render such member 22 in a condition to permit a flow of current therethrough to energize solenoids 16, 17, and 18; to operate the switches 2, 3, and 1. The circuits including the members 22 and their heating coils 23 are in parallel with each other and are open and closed by bridging contacts which are associated with the solenoids 15," 16, 17 and 18.

When the line switch 1 1 is closed, current passes through conductor 24, switch 25, conductor 26, solenoid 15, conductor 27, bridg mg contact28, conductor 29, to the negative slde of the line. This circuit being completed, the solenoid 15 will be energized, closing switch #1 and permitting current to pass through conductor 30, solenoid 31 of an overload relay 32, conductor 33, switch #1, through all of the sections 1", T and r of reslstance, and through the motor 10 to the negative side of the line. The motor 10 will thereupon start to rotate and accelerate un less there is an overload on the line, in which event the solenoid 31 of the overload relay will be excited to the extent that its core 34 Wlll be drawn up, opening the switch 25 and thus breaking the energizing circuit, causing switch #1 to open. and the motor to stop. When opened, the switch 25 is held 1n that position by a latch 35 having a reset coil 36. This latch 35 is employed for the purpose of holding the switch 25 in an open position, until definitely reset, to prevent any undersirable results occasioned by abobbing movement of the movable contact of the switch. Also when switch #1 is closed bridging contact 37 engages its cooperating contacts 38 and 39 closing a circuit from the positive side of the line through conductor 26, heating coil 23 of the time element device 19, bridging contact 40, conductor 27,

and bridging contact 28 to the negative side of the line. The branch or section including the resistance member 22 having the nega tive resistance coefficient and which is in parallel to the branch including the heating coil 23 takes no current at first, but as this member 22 becomes heated, due to the current passing through the heating coil 23, the effective resistance of this resistance memher is decreased, therefore gradually permitting current with increasing value to pass through the resistance member 22 and solenoid 16. When the current passing through this member 22 has reached a certain predetermined value the solenoid 16 becomes sufliciently energized to close switch #2 cutting out one section 1 ofthe resistance, and permitting the motor to increase its speed.

When switch #2 is closed, bridging contact member 43 engages its cooperating contacts 4:4 and 4L5 permitting current to flow through the heating coil 23 of resistance device 20, and the heating coil circuit of resistance device 19 is broken. As before, when current passing through heating coil 23 of resistance device 20 has heated the member 22 of device 20 sufficiently, current will pass through said energizing solenoid 17 to close the switch #3, cutting out the second section 1" of resistance and permitting the motor 10 to take on another increment of speed. Similarly upon the closing of the switch #3 bridging contact member 48 engages its cooperating contacts l9 and 50, permitting a flow of current through the heating coil of resistance device 21, and breaking the heating coil circuit of resistance device 2-0. lVhen the temperature of the resistance member 22 of device 21 is raised sufficiently, a current is caused to flow through solenoid 18 to close switch #4, cutting out the third and last section of resistance, and permitting the motor to speed up to its normal operating speed. The motor current now passes from the positive side of the line through conductor 30, solenoid 31, conductor 53, switch #4, and motor 10 to the negative side of the line. In this position with switch s i l closed all of the heating coils 23 are cut out of circuit and the energizing circuit includes conductor 24, switch 25, resistance 5%, bridging contact 55, solenoid 18, and conductor 29. The resistance 54 is in the circuit at this time for the purpose of cutting down the energizing current flow during the regular operation of the motor. By means of this arrangement, a sufficient time element is introduced in accelerating the motor to prevent any undesirable results. Any desirable time element can be obtained by merely substituting in the devices 19, 20, and 21 resistance members having different values than in the first place. The same end may be attained by increasing the heating effect on the resistance members so that current may pass through said resistance members in a shorter time than required in the first case. In Fig. 2, I have disclosed such an arrangement and which is a modification of my invention. Here the circuits including the heating coils are connected across the armature or so connected relatively to the armature that the heating effect of the coils varies in the same sense as the counter electromotive force. It is not necessarily to be understood that the heating effect of the coils on the resistance members increases directly proportionately to the increase of the counter electromotive force. This may or may not be true, but it is to be understood that the heating effect and counter electromotive force vary in the same sense. lVhen switch #5 is closed by the action of the current in the energizing circuit, the same as above described, the motor current passes through all of the sections r 1', and 1* of resistance. Bridging contact 60 closes, making such connections that the energizing circuit includes the heating coil 61, conductor 62,

bridging contact 63, conductor 64%, and a point 65 between the sections r and of resistance, forming the negative side of the line. It is therefore-seen with the switches in this position that the current running the motor passes through all of the sections of resistance, but the energizing circuit is bridged across the armature and only two sections 1" and 9' of resistance. As the motor speeds up the motor current decreases, thereby causing the C R drop across the resistance to decrease with a rise in the counter electromotive force which approaches the value of the impressed voltage. Therefore more current is forced through the heating coil 61 increasing its effect on the resistance member 66 so that current can pass through said resistance member to energize coil 67 closing switch #6 and cutting out section 7" of the resistance more readily than in the first case. The same operation is continued step by step until all of the sections of resistance are cut out of the motor circuit, permitting the motor to operate at its normal speed. This system illustrated in Fig. 2 is practically the same as that illustrated in Fig. 1, with the exception, however, of the modification outlined which provides for a more rapid successive operation of the switches.

It is evident that there may be other modifications in the precise arrangement here shown and described, and I intend to cover all such modifications which do not involve a departure from the spirit and scope of my invention.

hat I claim as new is:

1. In combination, a motor, a plurality of controlling switches therefor, means for causing the successive operation of said switches, said means including a plurality of solenoids controlling the separate actua tion of said switches, resistance members in series with said solenoids, and means for causing a variation in the resistance of said members.

2. An, automatic circuit controller comprising a plurality of switches. and time element means for controlling the operation of said switches, said means including a section of an electric circuit the resistance of which inherently varies with a change in temperature due to the current.

3. An automatic circuit controller comprising a plurality of switches, and time eloment means for successively controlling the operation of said switches, said means including a section of an electric circuit the resistance of which varies with a change in temperature due to the current.

4. An automatic circuit controller com prising a plurality of electromagnetic switches, and time element means for successively controllingthe operation of said switches, said means including a section of an electric circuit the resistance of which varies with rise in temperature due to the current.

5. An automatic circuit controller comprising a plurality of electromagnetic switches, a plurality of time element members for successively controlling the operation of said switches, said members including a section of an electric circuit the resistance of which varies with a change in temperature due to the current.

6. An automatic circuit controller comprising a plurality of electromagnetic switches, and time element devices for successively controlling the operation of said switches, said devices including a section of an electric circuit the resistance of which varies with a change in temperature due to the current, said section of each device being in series with corresponding magnet coils of said switches.

7. An automatic circuit controller comprising a plurality of electromagnetic switches each having an operating coil, and time element members in circuit with said operating coils for successively controlling the operation of each of said switches, said members forming a section of an electric circuit the resistance of which varies with-- change of temperature of said members due to the current.

8. An automatic circuit controller comprising a plurality of electromagnetic switches each having an operating coil, and time element devices having portions thereof in series with the operating coils for successively controlling the operation of said switches, said portions forming sections of an electric circuit the resistance of which varies with change in temperature due to the current.

9. An automatic circuit controller comprising a plurality of switches, and time element devices certain ones of which control the operation of certain ones of said switches, said devices including a section of an electric circuit the resistance of which varies with rise in temperature due to the current, and said devices being controlled by switches other than the ones whose operation is controlled by said devices.

10. In combination, a motor, a control switch therefor, a solenoid controlling the operation of said switch, a resistance in series with said solenoid, and means for causinga variation in the resistance to produce an operation of said switch whereupon said means becomes ineffective.

11. In combination with an electric motor, a plurality of sections of resistance in circuit therewith, switches adapted to cut sections of said resistance out of the motor circuit, time element means for controlling the operation of said switches, said means including sections of an electric circuit the resistance of which inherently varies with change in temperature due to the current, and means controlled by one of said switches for affecting the operation of the next succeeding switch.

12. In combination with an electric motor, of a plurality of sections of resistance in circuit therewith, switches adapted to cut sections of said resistance out of the motor circuit, time element members for controlling the operation of said switches, said members including sections of an electric circuit the resistance of which inherently varies with rise in temperature due to the current, and means controlled by one of said switches for deenergizing another of said switches.

13. A motor controller including a control switch, a solenoid controlling the operation of said switch, a resistance member in series with said solenoid, and means for causing a variation in the resistance of said member to produce an operation of said switch and so connected relatively to the motor armature that its effect varies in the same sense as the counter-electromotive force.

14:. In combination, a motor, a control switch therefor, a solenoid controlling the operation of said switch, a resistance member in series with said solenoid, a coil for causing a variation in the resistance of said member to produce an operation of said switch and so connected relatively to the motor armature that its efiect varies in the .100

same sense as the counter-electromotive force.

1 5. In a motor controller including a resistance, a control switch for cutting said resistance into and out of the motor circuit, a solenoid controlling the operation of said switch, a resistance member in series with said solenoid, and means for causing a variation in the resistance of said member to produce an operation of said switch and so connected relatively to the motor armature that its effect varies in the same sense as the counter-electromotive force.

v16. In combination, a motor, a resistance in the armature circuit thereof, and an automatic circuit controller for said motor comprising a plurality of switches, time element means for controlling the operation of said switches, said means including a section of an electric circuit the resistance of which varies with a change in temperature due to the current and another section which is in parallel with the armature of said motor but contains less armature resistance than is in series with said armature while said sections are effective to control the operation of said switches.

17. In combination, a motor, resistance in the armature circuit of said motor, and an automatic circuit controller for said motor comprising a plurality of switches, time element means for successively controlling the operation of said switches, said means including sections of an electric circuit the re sistance of which varies with change in temperature due to the current and parallel connected members for effecting a change in temperature, said parallel connected members also being in parallel with the armature of said motor but containing less of the armature resistance than is in series with said armature while they are acting to control the operation of said switches.

18. In combination, a motor, resistance therefor, an automatic circuit controller for said motor comprising a plurality of electromagnetic switches, time element members for successively controlling the operation of said switches, said members including sections of an electric circuit the resistance of which varies with rise in temperature due to the current and also sections which are in parallel with the armature of said motor but contain less armature resistance than is in circuit with said armature during the acceleration of said motor.

19. In combination, a motor, resistance therefor, and an automatic circuit controller for said motor comprising a plurality of electromagnetic switches, time element devices for successively controlling the operation of said switches and including sections of an electric circuit the resistances of which vary with rise in temperature due to the current and parallel connected members for effecting the rise in temperature, said sections being in series with the magnet coils of said switches, and said parallel connected members also being in parallel with the motor armature of said motor but containing less armature resistance than is in circuit with said motor armature during the time said members are effective to control the operation of said switches.

20. In combination, a motor, resistance in the armature circuit thereof, and an automatic circuit controller for said motor comprising a plurality of electromagnetic switches each having an operating coil, time element devices in circuit with said operating coils for controlling the operation of said switches, said devices including sections of an electric circuit the resistance of which varies with change in temperature due to the current and also sections which are in parallel with the armature of said motor but contain less armature resistance than is in series with said armature while said time element devices are effective in controlling said switches.

21. In combination, a motor, resistance therefor, and an automatic circuit controller for said motor comprising a plurality of electromagnetic switches each having an operating coil, time element devices for said operating coils for controlling the operation of said switches and including sections of an electric circuit the resistance of which varies with change in temperature due to the current, and also sections which are in parallel with the armature of said motor but contain less armature resistance than is in circuit with said armature during the time said sections are effective in controlling the operation of said switches.

22. In combination, a motor, resistance therefor, and an automatic circuit controller for said motor comprising a plurality of switches, time element devices controlling the operation of said switches and including sections of an electric circuit the resistance of which varies with change in temperature due to the current, and also sections which are in parallel with said motor but contain less armature resistance than is in circuit with said armature during the time said sections are effective to control the operation of said switches, said devices being con trolled by switches other than the ones said devices control.

23. An automatic'circuit controller, coinprising a plurality of electromagnetically actuated switches, and means for successively controlling the actuation of said switches, said means comprising a resistance element in the energizing circuit of the electromagnet of each switch, the resistance of said element decreasing from a maximum when the corresponding electromagnet circuit is closed to a value which causes the actuation of the corresponding switch.

2 In combination, a motor, and controlling means therefor comprising a switch, an electromagnet controlling the operation of said switch, a resistance element in the circuit of said electromagnet, and electrically energized means effective to produce a variation in the resistance of said element to cause operation of said switch, said electrically energized means being so connected relatively to the circuit of said motor that the effect of said means varies in the same sense as the counter-electromotive force of said motor.

In testimony whereof I afiiX my signature, in the presence of two witnesses.

HALFDAN A. STEEN.

"Witnesses:

CHAS. L. BYRON, ROB. E. SToLL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

